Method for working on sheet material and other objects

ABSTRACT

A method for working on sheet material or other objects uses a vacuum holddown device having a material-supporting surface including a plurality of vacuum openings passing therethrough. A vacuum chamber associated with the supporting surface applies a vacuum through the vacuum openings to the sheet material or other object received thereon. A sheet or panel of substantially airimpervious sheet material, such as a sheet of thin polyethylene, is spread over the exposed surface of the work, and cooperates with the vacuum to draw it toward the supporting surface and into a more compact condition. The air-impervious panel used with the vacuum may be an expendable sheet of such material spread entirely over the surface of the work prior to the performance of work thereon and/or may be one or two continuous belts of such material located in front of and/or behind the work tool. The vacuum and air-impervious panel may also be used to hold a layup of sheet material to be cut in a compact condition for a long period of time between the laying up process and the cutting process to prevent the various layers of the layup from shifting, flowing or otherwise moving relative to one another so as to depart from their relative positions as initially laid up.

United States Patent [72] Inventors Heinz Joseph Gerber;

David R. Pearl, both of West Hartford, Conn. [21] Appl. No. 7,544 [22] Filed Feb. 2, 1970 Division of Ser. No. 821.780, .\lay 5. 1969. Pat. No. 3.495.492 [45] Patented Aug. 10, 1971 [73] Assignee Gerber Garment Technology East Hartford, Conn.

[54] METHOD FOR WORKING ON SHEET MATERIAL AND OTHER OBJECTS 6 Claims, 9 Drawing Figs.

[52] U.S.Cl 83/14, 83/29, 83/451, 83/925 CC, 269/21 [51] Int. Cl 826d 7/02 [50] FieldofSearch 83/14, 19, 29, 22, 374, 451,422, 424, 428, 648-650, 176, 925 CC; 270/30, 31; 269/21 [56] References Cited UNITED STATES PATENTS 933,688 9/1909 Atwood 83/451 as, 40 38 9e VACUUM SOURCE Primary Examiner-James M. Meister An0rneyMcCormick, Paulding & Huber ABSTRACT: A method for working on sheet material or other objects uses a vacuum holddown device having a material-supporting surface including a plurality of vacuum openings passing therethrough. A vacuum chamber associated with the supporting surface applies a vacuum through the vacuum openings to the sheet material or other object received thereon. A sheet or panel of substantially air-impervious sheet material, such as a sheet of thin polyethylene, is spread over the exposed surface of the work, and cooperates with the vacuum to draw it toward the supporting surface and into a more compact condition. The air-impervious panel used with the vacuum may be an expendable sheet of such material spread entirely over the surface of the work prior to the performance of work thereon and/or may be one or two continuous belts of such material located in front of and/or behind the work tool. The vacuum and air-impervious panel may also be used to hold a layup of sheet material to be cut in a compact condition for a long period of time between the laying up process and the cutting process to prevent the various layers of the layup from shifting, flowing or otherwise moving relative to one another so as to depart from their relative positions as initially laid up.

FIG. 1

Patented Aug. 10, 1971 4 Shoots-Sheet 1 II 1 mill! W" 0000000 000000 a O aoooooooooooooooeo 00000000120000000000 OOODOOOOOOQOOOOOOO 000000000000000000 00000000000000 00000 llllllll min Will" I .Ill[ I o n INVEN'I ORS HEINZ JOSEPH GERBER DAVID R. PEARL ATTORNEYS Patented Aug. 10, 1971 4 Shoots-Sheet 2 INVENTORS HEINZ JOSEPH GERBER DAVID R. PEARL BY %W/ ATTORNEYS Patented Aug. 10, 1971 3,598,006

4 Sheets-Sheet 5 Patented Aug. 10, 1971 3,598,006

4 Sheets-Sheet 4,

X a x 124 no METHOD FOR WORKING ON SHEET MATERIAL AND OTHER OBJECTS CROSS REFERENCE TO RELATED APPLICATION This application is a division of copending application Ser. No. 82l,780, filed May 5, I969 for Apparatus for Working on Sheet Material.

BACKGROUND OF THE INVENTION This invention relates to methods for working on sheet material and other objects, and deals more particularly with an improved method for cutting sheet material such as gar ment and upholstery fabrics.

The general aim of the present invention is to provide an improved method of the aforedescribed type and which is particularly well adapted to be used with automatically controlled work tools such as an automatically controlled fabric cutter.

SUMMARY OF THE INVENTION In accordance with the method of the invention an object such as a layup of sheet material is spread or placed onto a supporting surface and at least a portion thereof covered with a sheet or panel of substantially air impcrvious material. Vacuum is then applied to the air impervious panel through the supporting surface and through the object, if it is porous, to pull the panel toward the supporting surface thereby holding it in a relatively rigid or firm condition for cutting or other work by means of an automatically positioned cutting tool or the like, the vacuum being applied at least in the vicinity of the tool. In case of material such as loose knits, the layers ofwhich tend to shift relative to one another following layup, a sheet of air-impervious material is preferably applied over the layup immediately after the laying-up process is completed and a vacuum thereafter immediately applied and held until the layup is cut which may be at much later date, the compacting effect of the vacuum and air-impervious panel tending to prevent shifting or flowing of the material which would otherwise take place.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary plan view of apparatus embodying the present invention and illustrating a method for practicing the invention,

FIG. 2 is a fragmentary side elevational view of the ap paratus of FIG. 1.

FIG. 3 is a fragmentary perspective view partially in section taken generally along the line 3-3 of FIG. 2.

FIG. 4 is a sectional view taken generally along the line 4 4 of FIG. 2.

FIG. 5 is a schematic side view of apparatus comprising another embodiment of this invention.

FIG. 6 is a schematic side view of apparatus comprising another embodiment of this invention.

FIG. 7 is a schematic side view showing apparatus comprising yet another embodiment of thisinvention.

FIG. 8 is a schematic side view of apparatus comprising still another embodiment of this invention.

FIG. 9 is a schematic side view of apparatus comprising still another embodiment ofthis invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Turning now to the drawings, and first considering FIGS. I to 4, an apparatus for working on fabric and other sheet materials in accordance with the invention is indicated generally at I0. The apparatus 10 is particularly adapted to spread or layup sheet material and to cut the material in response to input signals supplied. to the apparatus by an as sociated control means such as,-for example, a computerized or numerically controlled controller (not shown). More par ticularly, the apparatus It) comprises an elongated vacuum holddown table indicated generally by the reference numeral I2 to provide support fora layup 14 which comprises layers of sheet material arranged in facc-to-facc or faceup vertically stacked relation. A spreading tool indicated generally at I6 and supported for movement longitudinally of the table in response to signals supplied by the controller serves to spread sheet material to form the layup 14. A cutting tool designated generally by the reference numeral 18 is supported to traverse the surface of the table I2 in two coordinate directions in dicated by the arrows X and Y in response to position signals supplied by the controller. The cutting tool may take various forms but preferably, and as shown, it includes a blade I9 supported for vertically reciprocating movement in cutting engagement with the layup 14, The blade 19 is movable along any line which may be straight or curved as required in cutting a garment component or the like and is further arranged for rotation about its own axis in a direction indicated by the arrow 0 and for vertical movement into and out of cutting engagement with the layup I4.

The apparatus 10 also includes means for applying vacuum to the holddown table to position and smooth or remove, wrin kles from the sheet material as it is spread and to hold it firmly in position on the table during the cutting operation. The latter means is responsive to longitudinal movement of either tool, as will be hereinafter further discussed.

Considering the apparatus I0 in further detail, the table 12 comprises a generally horizontally disposed base plate 20 supported at convenient working height by a plurality of legs 22, 22. On the upper surface of the plate 20 there is mounted a generally rectangular frame 24 formed by longitudinally extending side members 26, 26 and transversely extending end members (not shown). A vertical spacing member 30 positioned inwardly adjacent each side member 26 extends longitudinally of the table between the end members to provide support for a perforated plate 32. Preferably, the plate 32 is made from expanded metal and spaced above the plate 20 and below the upper or free edge ol'the frame 24. A longitudinally spaced series of partitions 34, 34 extends transversely of the frame 24 between the spacers 30, 30 and the plates 20 and 32 to define a longitudinal series of chambers 36, 36 between the latter plates as best shown in FIG. 4.

A bed of material 38 is supported in the frame 24 by the plate 32 and has an upwardly facing fabric-supporting surface V 40 which includes a longitudinal series of fabric-supporting zones 4!, 4I. Each zone 41 is associated with and located above a chamber 36. Various materials may be used to form the bed 38, but preferably it comprises a resilient low density cellular polyethylene plastic material which may be readily penetrated by the blade I). The blade I9 is preferably ad justed to penetrate the table to assure accurate and efficient cutting of the lower layers comprising the layup. Ethafoam, a product of Dow Chemical Company, has proven particularly suitable as a bed material. The bed material includes a plurali ty of passageways passing therethrough for conducting vacuum from the chambers 36, 36 to the upper surface of the bed material which supports the material to be cut. If the bed material is porous, as for example a foamed plastic with an open cell structure, the porosity of the material may be used to provide these passageways. Preferably, however, the bed material is one which is substantially nonporous, as for example, a foamed plastic with a closed cell structure, and the vacuum-transmitting passageways consist of vertically extend ing passageways 42', 42 as shown, drilled or otherwise formed in the bed and passing therethrough generally perpendicular to the supporting surface. As shown, each passageway at its upper end or in the plane of the supporting surface 40 terminates in an opening 44.

Vacuum is applied to the table 12 by a vacuum chamber or duct 46 which extends longitudinally of the table below the plate 20 and is connected to a suitable vacuum source 45 through a conduit 47, the vacuum source preferably being one of high flow rate capacity. A longitudinally spaced series of slots or ports 48, 48 formed in the plate 20 communicate with the duct 46 and with each of the chambers 36, 36. In the illustrated embodiment, two ports 48, 48 communicate with each chamber 36. v

Application of vacuum to the table 12 is controlled by a plurality of slide valves 50, 50 mounted on the upper surface of the plate 20. Each valve 50 is associated with a pair of ports 48, 48 and is arranged for transverse sliding movement on the plate 20 between open and closed positions indicated respectively at 50 and 50 in HO. 1. Each valve is biased toward its closed position by a spring 52 and moveable to its open position in response to force applied to the free end of an associated control rod or follower 54 which projects from the body of the valve, passes through an associated spacer 30 and side member 26, and projects outwardly beyond the side. member. Control means are also provided for maintaining the vacuum applied to the passageways of the bed 38 at a substantially constant predetermined level despite changes in the flow rate of air therethrough. As shown in FIG. 4 this control means comprises a pressure sensor 49 in the vacuum duct 46, a control valve 51 in the conduit 47 and a controller 53. The controller 53 is responsive to the sensor 49 to operate the valve 51 as required to maintain a constant level of vacuum in the duct 46, the level maintained being adjustable by means of a set-point adjustment member 55 on the controller 53.

The spreader 16 is of a generally conventional type for faceto-face or faceup spreading of rolled fabric or other sheet material and comprises a supporting carriage 58 arranged to travel on rollers 60, 60 which engage ways 62, 62 fastened to and extending longitudinally of the table 12. Additional rollers 63, 63 mounted on the carriage 58 engage the inner sides of the ways 62, 62 to maintain the carriage in longitudinal alignment with the table 12. A roll or bolt of material designated at 64 is supported by a rod 66 which extends transversely of the carriage 58. A drive motor 68 mounted on the carriage and responsive to input signals from the controller carries a pinion 70 which engages a longitudinally extending rack 72 mounted on the table 12 to drive the carriage in the X direction. The carriage also has an elongated cam element 73 which includes a cam surface 74 adapted to engage and move each successive follower 54 as the carriage 58 moves longitudinally of the table. The cam surface 74 is of somewhat greater longitudinal extent than the longitudinal distance between three successive followers 54, 54. Thus, as the carriage 58 moves longitudinally of the table 12, the followers 54, 54 are successively engaged and each valve 50 is moved to and held in its open position until the cam surface 74 engages and opens the next succes sive valve 50.

The blade 19 is driven in cutting engagement with the layup 14 by a drive unit 76 supported for movement transversely of the table [2 by a moveable supporting carriage 78 which bridges the table. The drive unit 76 is arranged to raise and lower the blade 19 relative to the table surface 40 and to move in its Y and 0 directions in response to input signals from the controller as the carriage simultaneously moves the drive unit and blade in the X direction. Each end of the carriage is sup ported by a pair of rollers 80, 80 which travel on an associated way 62. A drive motor 84 secured to the carriage 78 and responsive to input signals from the computer carries a pinion 86 which engages the rack 72 to drive the carriage in the X direction. The carriage 78 also includes an elongated cam element 86 secured to one side thereof which his a cam surface 88 for engaging the followers 54, 54 to move the valves 50, 50 to their open positions. The longitudinal dimension of the cam surface 88 is at least equal to the longitudinal distance between four successive cam followers 54, 54. Thus, when the valve 50 associated with the cutting zone in which the blade 19 is operating is in its open position the valves associated with the zones adjacent the cutting zone will also be open. In FIG. I the cutting zone is designated at 41 Preferably, the cutting tool carries at least one panel adapted to overlie an associated portion of the upper surface of the layup 14 as the cutting tool moves longitudinally of the table [2. The illustrated apparatus includes two longitudinally spaced-apart panels or endless belts 90, 90 positioned at opposite sides of the blade 19, Each belt 90 is made from nonpermeable plastic and supported by a pair of longitu dinally spaced rollers 92, 92 journaled for rotation about transversely extending axes by arms 94, 94 which project longitudinally and in opposite directions from opposite sides of the carriage. The belts 90, 90 are preferably arranged for vertical adjustment relative to the carriage to accommodate layups or stacks of material of various height. so that the belts will rest on the upper surface of the material as the cutting tool 18 travels longitudinally relative to the table 12.

Considering now the operation ofthe apparatus H], the spreading tool l6 and the cutting tool is are independently operative and when one of the tools is in operation the other is or may be positioned in an inactive area at one or the other end of the table T2, or, if desired, a transfer device (not shown) may be provided to move the tool not in use to a suitu ble storage position away from the table.

The spreading tool 16 moves in the X direction in response to input signals from the controller as sheet material is paid out from the bolt 64 in conventional manner. As the spreading tool advances each valve 50 in its path of travel is successively opened by the cam element 73 so that vacuum is applied to a table zone 41 in which the material is being spread. Each valve 50 remains in its open position until the cam element 73 en gages and opens the next successive valve. Thus, the vacuum holddown table 12 exerts a substantially continuous smoothing effect upon sheet material as it is spread longitudinally of the table surface. When the material is of a porous type, such as a woven fabric, vacuum acts upon an associated region of the lower surface of the fabric as it is brought into contact with the table surface 40 and also acts through the lower layers of fabric to exert smoothing effect upon an as sociated region of the lower surface of each successive upper layer comprising a layup.

When a layup of porous material is to be cut a substantially imperforate or air-impervious expendable panel 96 which may be readily cut by the blade 19 is preferably first positioned in overlying relationship with the layup as shown in FIGS. 3 and 4. The panel is imperforate in the sense that it is substantially impervious to the passage of air therethrough. Relatively thin flexible plastic film, such as polyethylene sheet, has provcn particularly satisfactory for this purpose. When desirable to support fabric layups with thin or weak edges, longitudinally extending guide blocks 98, 98 are positioned adjacent the side edges of the layup before the panel 96 is positioned thereon. These blocks are preferably made of the same material as the bed 38, and in any event are made of a material which may readily be cut into by the cutting tool without damage to the tool. These guide blocks are not, however, necessary in all cases and when not used the panel 96 is spread so as to merely drape over the edges of the fabric layup. In either event the panel is preferably of such a size and so spread as to extend transversely across the full width of the layup, down both sides thereof and across a portion of the supporting surface 40 of the bed adjacent the sides ofthe layup, thereby completely en veloping the layup.

At the start of the cutting process, the blade I) is elevated or raised to a position above and moved to a preselected start ing position relative to the upper surface of the layup. Thereafter, the blade is lowered to penetrate the layup and the cutting cycle proceeds in accordance with its programmed pattern. As the carriage 78 moves in the X direction, it will be noted that the valve 50 associated with the cutting zone 41' lr.

in its open position so that vacuum is applied to the surface 40 in the latter zone. lt will be further noted that the valves 50,50 associated with zones 4|, 4] immediately adjacent the cutting zone 41' will also be in their respective open positions so that vacuum is also applied in latter zones. Vacuum is applied to both the lower surface of the porous material to be cut and through the latter material to the lower surface of the panel 76.

Vacuum is therefore applied to the lower surface of the material to be cut and when such material is porous the vacuum passes through and around such material to the lower surface of the air-impervious panel 76 and causes such panel to be attracted toward the supporting surface to compress or compact the layup. When the material of the layup is non porous, the vacuum nevertheless passes around such material and applies a vacuum to the lower surface of the panel 76 to produce the same compressing or compacting effect.

The application of vacuum in the above-described manner to compress or compact the layup causes the layup to assume a relatively rigid or firm condition with the individual layers of the layup being held tightly relative to one another so as not to shift or move during the cutting process. The compressing or compacting of the layup also has the additional advantage of normalizing"the layup. That is, fabrics or other materials of different consistencies, particularly those with loose consistencies such as loose weaves, quilted fabrics and knitted goods. are compressed, according to their fluffiness or weight, to a somewhat normal or standard consistency so as to react in a generally uniform manner to the cutting action of the blade, that is, the compacting effect tends to make all materials substantially uniform as far as their reaction to the blade is concerned so that substantially the same cutting tool, feed rate, etc, may be used for many different materials. The amount of fabric compression attained from the application of a given vacuum will, of course, vary. In some instances, the free stack height of a given layup of fabric may be reduced significantly, as for example from to 50 percent, so that a relatively short cantilevered blade may be used.

It should also be noted that another benefit achieved by the above-described apparatus is that as vacuum is applied to the lower surface of the layup cooling air is drawn downwardly through the slit in the fabric around and behind the blade thereby cooling the blade as it advances in its programmed pattern.

FIG. 5 shows a cutting apparatus, indicated generally at 100, which utilizes a vacuum to hold the fabric or other sheet material while it is being cut but wherein the movement of the cutter relative to the sheet material in one of its two coordinate directions of relative movement is obtained by holding the cutter stationary in such coordinate direction and by instead moving the sheet material bodily in such coordinate direction. The cutter 102 includes a reciprocating blade 104 and operates in conjunction with a bed of penetrablc material 106 having a supporting surface 108 on which is received the fabric layup 110. In the cutting zone the bed of-penetrable material 106 and the fabric layup 110 is supported by an endless belt conveyor 112 located between two other belt conveyors 114 and 116. The belt of the conveyor 112 is porous and immediately below the cutter 102 a vacuum is applied to the fabric layup 110, through the belt ofthe conveyor 1 12 and through the bed of penetrable material 106, by an open topped vacuum chamber 120 connected to a source of vacuum through the conduit 122. Cooperating with the vacuum chamber 120 is a sheet of air-impermeable material 124 which overlies the fabric layup 110 and which is pulled toward the supporting surface 108 "by the vacuum to compress and hold the fabric layup in a suitable condition for cutting by the cutter. If desired, and as illustrated, additional vacuum chambers 126 and 128 may be located on opposite sides ofthe vacuum chamber 120 to apply a vacuum to a larger area ofthe fabric layup 110, these latter vacuum chambers being connected to the source of vacuum by the conduits 130 and 132, respectively. Either in addition to or in place of the air impermeable sheet 124 the apparatus 100 of FIG. 5 may include two endless belts 134 and 136 of air-impermeable material, similar to the endless belts 90, 90 of FIG. 1, for cooperation with the vacuum applied to the layup to hold the layup in a condition for cutting.

FIG. 6 shows a cutting apparatus indicated generally at 200 having a cutter, indicated generally at 202, utilizing a cutting blade 204 which passes entirely through the bed 106 of penetrable materials used to support the fabric layup 110. The cutter 202 has one main portion 208 located below the bed 106 of supporting material and another main portion 208 located below the bed 106. The cutter 202, may for example, be a bandsaw cutter with the blade 204 having adjacent uptraveling and down-traveling runs and with the portions 206 and 208 being the pulleys, guide rolls, motors and the like required for supporting and driving the blade. The cutter 202 may also be a jigsaw-type cutter with the blade 204 being reciprocated vertically along its longitudinal axis. In the vicini ty ofthe blade 204 the bed 106 is supported by two small belt conveyors 210 and 212 which are spaced from one another longitudinally of the bed 106 to form a gap 214 therebetween through which the blade 204 passes. A vacuum chamber defining means, indicated generally at 216, is located below the bed 106 in the vicinity ofthe cutter 202 and encloses both the lower portion 208 ofthe cutter and the two conveyors 210 and 212. The vacuum chamber defined by the means 216 is connected to a suitable source of vacuum and applies a vacuum to the under surface of the bed material 106 which vacuum passes therethrough and acts on the panel 124 to pull said panel toward the supporting surface 108 to compress the layup 110. The belts of the conveyors 210 and 212 are porous so that air may flow therethrough.

FIG. 7 shows an apparatus, indicated generally at 220, which is generally similar to that of FIG. 6, except that in the vicinity of the cutter 202 the bed of supporting material 106 is supported by a belt conveyor, indicated generally at 222, having a belt 224 with an upper run 226 which supports the bed 106. Along the upper run 226 the belt 224 is trained into a downwardly extending loop 228, by a number of rollers 230, 230, which loop surrounds the lower portion 208 of the cutter. The two upper rollers 230, 230 are located close to the blade 204 so as to form a small gap 232 therebetween through which the blade 204 passes. The belt 226 is porous and the entire loop 228 and the lower portion 208 of the cutter is surrounded by a vacuum-chamber-defining means or housing 234 which applies vacuum to the lower surface of the bed 106 in the vicinity of the cutter 202. If desired two additional vacuum chambers 236, 236 may be located on opposite sides of the main chamber 230 to apply vacuum to a greater extent of the supporting bed 106.

FIG. 8 shows a cutting device, indicated generally at 254, utilizing a rotary drum, indicated generally at 236, having a porous cylindrical wall 258. A bed of supporting material 260 is received on and surrounds the exterior surface of the drum wall 258, the material 260 preferably being plastic foam and having air conducting passages extending therethrough from its radially inner surface to its radially outer surface 262. The drum 256 is so arranged that a portion of the layup travels thereover and as the drum is rotated the layup and its as sociated air-impervious overlay sheet 124 is moved in the X direction as indicated by the arrow in FIG. 8. The cutter 102 is movable in the Y direction. To assist in supporting and moving the layup in the X direction, the apparatus further includes two small belt conveyors 264 and 266 located on opposite sides of the drum. In the vicinity of the drum 2S6 vacuum is applied to the bottom surface of the layup 110 by a vacuum chamber defining means or housing 268 located within the drum and having an upwardly facing opening which exposes that portion ofthe cylindrical wall 258 registered therewith to the vacuum therein. Additional vacuum chambers 270 and 272 may be used on either side of the drum 256 for producing a vacuum over a greater extent of the layup 110. The chambers 270 and 272 preferably enclose respectively the conveyors 264 and 266, as shown.

FIG. 9 shows a cutting apparatus 240 in which the air-inn pcrvious sheet 124 which is used to overlie the layup 110 is trained in a traveling loop over the cutter 102 so as to permit the sheet 124 to overlie the entire exposed surface ofthe layup while nevertheless avoiding the necessity for cutting such sheet with the cutting tool. As shown in this figure, the air-impervious sheet 124 is trained over the cutter 102 and into a loop by four rollers 242, 242, supported by an associated housing 244. Between the rollers the sheet is backed up by plates 246, 246 and 248 to resist the tendency of the loop to collapse toward the cutter by the vacuum existing within the loop. The housing 244, rollers and backing plates travel with the cutter 202 in the X direction as indicated by the arrow, and the cutter 102 moves in the Y direction. In FIG. 9, the bed of supporting material 106 is shown supported on a perforated wall 250 below which is one or more vacuum chambers such as shown at 252, for applying vacuum to the bed material,

We claim:

I. A method for working on an object, said method comprising the steps of placing said object on a supporting surface. positioning a substantially air-impervious panel in overlying relation with at least a portion of the exposed surface of said object, producing a vacuum directly adjacent the surface of said air-impervious panel facing said object so that atmospher ic pressure acting on said panel pushes it toward said object and causes said object to be compressed between said panel and said supporting surface, and thereafter working on said object in the vicinity of said panel while said vacuum is applied theretov 2. A method for cutting a layup ofshect material comprising the steps of placing said layup in spread condition on a sup porting surface, positioning a substantially airimpcrvious panel in overlying relation with at least a portion of the ex posed surface of said layup, producing a vacuum directly adjacent the surface of said air-impervious panel facing said layup so that atmospheric pressure acting on said panel pushes it toward said layup and causes said layup to be compressed between said panel and said supporting surface, and thereafter cutting said layup in the vicinity of said panel while said vacuum is applied thereto,

3. A method for cutting sheet material comprising the steps of placing sheet material in spread condition on a supporting surface, providing a cutting tool movable relative to said sheet material in the plane thereof for cutting the same, positioning a substantially air-impervious panel in overlying relation with the exposed surface of said sheet material at least in a zone adjacent said cutting tool, producing a vacuum directly adjacent the surface of said air-impervious panel facing said sheet material so that atmospheric pressure acting on said panel pushes it toward said sheet material and causes said sheet material to be compressed between said panel and said sup porting surface at said zone, and cutting said sheet material with said cutting tool while said vacuum is applied thereto.

4. A method for working on sheet material comprising the steps of spreading a layup of sheet material onto a supporting surface, positioning a substantially air-impervious panel in overlying relation with the exposed surface of said layup, producing a vacuum directly adjacent the surface of said airimpervious panel facing said layup so that atmospheric pressure acting on said panel pushes it toward said layup and causes said layup to be compressed between said panel and said supporting surface, maintaining said vacuum for a rela tively long period of time in comparison to the period of time required for spreading said layup onto said supporting surface so as to hold said layup in a compressed state during such relativcly long period of time, and thereafter cutting said layup at the end of said relatively long period of time.

5. A method for working on sheet material as defined in claim 4 further characterized by maintaining said vacuum at least in the vicinity of the cutting zone while performing sand step of cutting said layup.

6. A method for cutting a layup of sheet material as defined in claim 2 further characterized by said layup which is placed on said supporting surface being comprised of sheets of porous material, and said step of producing a vacuum directly adjacent the surface of said airimpervious panel facing said layup being performed by producing a vacuum adjacent said supporting surface which latter vacuum is transmitted to said air-impervious panel through said porous material of said layup.

UNITED STATES PATENT OFFICE Certificate Patent No. 3,598,006 Patented August 10, 1971 Heinz Joseph Gerber and David R. Pearl Application having been made by Heinz Jose h Gerber and David R. Pearl the inventors named in the patent above ldentified, an Gerber Garment Technology, East Hartford, Conn, a corporation of Connecticut, the assignee, for the issuance of a certificate under the provisions of Title 35, Section 256, of the United States Code, deleting the name of David R. Pearl as a joint inventor, and a showing and proof of facts satisfyilig the requirements of the said section having been submitted, it is this 20th day of a rch 1973, certified that the name of the said David R. Pearl is hereby deleted from the said patent as a joint inventor with the said Heinz Joseph Gerber.

FRED W. SHERLIN G Associate Solicitor. 

1. A method for working on an object, said method comprising the steps of placing said object on a supporting surface, positioning a substantially air-impervious panel in overlying relation with at least a portion of the exposed surface of said object, producing a vacuum directly adjacent the surface of said airimpervious panel facing said object so that atmospheric pressure acting on said panel Pushes it toward said object and causes said object to be compressed between said panel and said supporting surface, and thereafter working on said object in the vicinity of said panel while said vacuum is applied thereto.
 2. A method for cutting a layup of sheet material comprising the steps of placing said layup in spread condition on a supporting surface, positioning a substantially air-impervious panel in overlying relation with at least a portion of the exposed surface of said layup, producing a vacuum directly adjacent the surface of said air-impervious panel facing said layup so that atmospheric pressure acting on said panel pushes it toward said layup and causes said layup to be compressed between said panel and said supporting surface, and thereafter cutting said layup in the vicinity of said panel while said vacuum is applied thereto.
 3. A method for cutting sheet material comprising the steps of placing sheet material in spread condition on a supporting surface, providing a cutting tool movable relative to said sheet material in the plane thereof for cutting the same, positioning a substantially air-impervious panel in overlying relation with the exposed surface of said sheet material at least in a zone adjacent said cutting tool, producing a vacuum directly adjacent the surface of said air-impervious panel facing said sheet material so that atmospheric pressure acting on said panel pushes it toward said sheet material and causes said sheet material to be compressed between said panel and said supporting surface at said zone, and cutting said sheet material with said cutting tool while said vacuum is applied thereto.
 4. A method for working on sheet material comprising the steps of spreading a layup of sheet material onto a supporting surface, positioning a substantially air-impervious panel in overlying relation with the exposed surface of said layup, producing a vacuum directly adjacent the surface of said air-impervious panel facing said layup so that atmospheric pressure acting on said panel pushes it toward said layup and causes said layup to be compressed between said panel and said supporting surface, maintaining said vacuum for a relatively long period of time in comparison to the period of time required for spreading said layup onto said supporting surface so as to hold said layup in a compressed state during such relatively long period of time, and thereafter cutting said layup at the end of said relatively long period of time.
 5. A method for working on sheet material as defined in claim 4 further characterized by maintaining said vacuum at least in the vicinity of the cutting zone while performing said step of cutting said layup.
 6. A method for cutting a layup of sheet material as defined in claim 2 further characterized by said layup which is placed on said supporting surface being comprised of sheets of porous material, and said step of producing a vacuum directly adjacent the surface of said air-impervious panel facing said layup being performed by producing a vacuum adjacent said supporting surface which latter vacuum is transmitted to said air-impervious panel through said porous material of said layup. 